1. University Children's Hospital Regensburg (KUNO) Regensburg Germany
2. Member of the Research and Development Campus Regensburg (WECARE) Hospital St. Hedwig of the Order of St. John Regensburg Germany
3. University Department of Gynecology and Obstetrics Hospital St. Hedwig of the Order of St. John, University Medical Center Regensburg Regensburg Germany
4. Institute of Social Medicine and Health Systems Research Otto von Guericke University Magdeburg Magdeburg Germany